bollu
commented
5 years ago Yes, for example, here is an example of factorial (taken from bench/factorial-worker-wrapper-optimised.stg) from commit:
https://github.com/bollu/simplexhc-cpp/tree/a40f6ab299e0f4c9e0b195512422b7ee5855c950:
╭─bollu@strangeattractor ~/work/simplexhc-cpp/bench ‹master›
╰─$ cat factorial-worker-wrapper-optimised.stg
# RUN: %loadSimplexhc %s --jit | FileCheck %s
# CHECK: 120
binding factorial = \(a : PrimInt) -> PrimInt {
case a () of
0 -> 1;
x -> case primSubtract (x 1) of
xmin1 -> case factorial (xmin1) of
factxmin1 -> primMult (x factxmin1);;;
};
binding main = \() -> Boxed {
case factorial (5) of
x -> printInt (x);
};Execute:
╭─bollu@strangeattractor ~/work/simplexhc-cpp/bench ‹master›
╰─$ ../build/sxhc factorial-worker-wrapper-optimised.stg -O 3 --emit-llvm > fact.lland then view the IR:
define fastcc void @main(i8* nocapture readnone) #0 {
entry:
tail call void @printOnlyInt(i64 120)
%nReturnFrames.i.i = load i64, i64* @stackReturnTop, align 8, !invariant.group !0
%haveReturnFrames.i.i = icmp ugt i64 %nReturnFrames.i.i, 1
br i1 %haveReturnFrames.i.i, label %callnextfn.i.i, label %"case_factorial(atom-5)_alts.exit"
callnextfn.i.i: ; preds = %entry
%next_cont.i.i = tail call fastcc i8* @popReturn()
%cont_slot.i.i.i = bitcast i8* %next_cont.i.i to void (i8*)**
%cont.i.i.i = load void (i8*)*, void (i8*)** %cont_slot.i.i.i, align 8, !invariant.group !0
tail call fastcc void %cont.i.i.i(i8* %next_cont.i.i)
br label %"case_factorial(atom-5)_alts.exit"
"case_factorial(atom-5)_alts.exit": ; preds = %entry, %callnextfn.i.i
ret void
} which has been reduced to a constant printInt 120 call and the final epilogue cleanup of deciding to not continue any more.
csabahruska
Do you have any example when LLVM with pointer analysis can remove laziness as much as GRIN can?
i.e.